Cyclical changes in sperm volume during in vitro incubation under capacitating conditions: a novel boar semen characteristic

Reproduction ◽  
2000 ◽  
pp. 283-293 ◽  
Author(s):  
AM Petrounkina ◽  
RA Harrison ◽  
R Petzoldt ◽  
KF Weitze ◽  
E Topfer-Petersen

The osmotic reactivity of boar spermatozoa during incubation in vitro was studied using a hypo-osmotic swelling test in conjunction with electronic measurement of cell volume. Sperm populations showed fluctuations in both iso-osmotic cell volume and hypo-osmotic volume response that fitted mathematical models for periodicity. Significant differences of frequency and amplitude were observed during sperm incubation under capacitating conditions as compared with those under non-capacitating conditions. In addition, different boars showed specific differences in their fluctuation characteristics under capacitating conditions. During incubation under capacitating conditions, a decrease in osmotic reactivity was observed that correlated with a decrease in motility, while the absolute value of the earliest maximum of the osmotic-induced response correlated with an increase in the proportion of discharged acrosomes. The time course of the cyclical behaviour of osmotic reactivity may be a useful parameter for assessing boar sperm response to capacitating conditions.

2005 ◽  
Vol 17 (2) ◽  
pp. 305
Author(s):  
I. Parrilla ◽  
J.M. Vazquez ◽  
M.A. Gil ◽  
I. Caballero ◽  
C. Almiñana ◽  
...  

Addition of seminal plasma (SP) to the collection medium has been shown to be beneficial for motility and viability of sex-sorted and stored spermatozoa. However, SP could not only delay but also decrease the in vitro fertilization rates of IVM pig oocytes. In the present study, the time-course of IVM pig oocyte penetration of sex sorted boar spermatozoa stored in the presence or absence of SP was evaluated. Spermatozoa were sex-sorted following the Beltsville sperm sexing technology (Johnson and Welch 1999 Theriogenology 52, 1323–1342) and collected in TEST-egg yolk buffer (2%) with (10%) or without (control) SP. Sex-sorted spermatozoa were stored at 20°C during 0, 2, 5, and 10 h after sorting. Oocytes were matured in vitro in NCSU23 (Peters and Wells 1663 J. Reprod. Fertil. 48, 61–73) for 44 h in 5% CO2 in air at 39°C. The in vitro penetration time-course was determined by co-incubating the sex-sorted and stored spermatozoa with IVM oocytes during 3, 6, and 18 h in modified TRIS-buffered medium (mTBM) (Abeydeera and Day 1997 Theriogenology 48, 537–544) at 39°C in an atmosphere of 5% CO2 in air. Penetration rates and number of spermatozoa per oocyte were assessed after fixation and staining of the oocytes. Statistical analyses were conducted by ANOVA. Presence of SP did not delay the onset of the oocyte penetration. Moreover, at 3 h of co-incubation, SP increased (P < 0.05) both penetration rates and mean number of spermatozoa per oocyte in sorted and stored boar spermatozoa when compared with control (45 vs. 20, 50 vs. 32, 38 vs. 23, 15 vs. 8, at 0, 2, 5, and 10 h of storage with SP and control, respectively). High penetration rates were reached after 6 h of co-incubation (82 vs. 51, 96 vs. 76, 83 vs. 48, 31 vs. 24, at 0, 2, 5, and 10 h of storage with SP and control, respectively) in sorted and stored samples, with no further increase at 18 h (70 vs. 63, 92 vs. 79, 87 vs. 53, 55 vs. 40, at 0, 2, 5, and 10 h of storage with SP and control, respectively). Spermatozoa stored 2 h in the presence of SP showed the best penetration rate and highest mean number of spermatozoa per oocyte. The mean number of spermatozoa per oocyte increased as the co-incubation time increased (ranging from 2.1 to 5.8 for sorted spermatozoa stored 2 h in the presence of SP at 3 h and 18 h of co-incubation, respectively). In conclusion, the presence of SP during the storage of sex-sorted spermatozoa improves their in vitro fertilizing ability without affecting the onset of the oocyte penetration time. This work was supported by DGICYT (AGL 2001-0471), Fundación Seneca (PB174/FS/02) and CTIC (2103SIU0040).


Reproduction ◽  
2004 ◽  
Vol 127 (1) ◽  
pp. 105-115 ◽  
Author(s):  
A M Petrunkina ◽  
M Hebel ◽  
D Waberski ◽  
K F Weitze ◽  
E Töpfer-Petersen

Osmotically induced cell swelling triggers a chain of events leading to a net loss of major cell ions and water, resulting in cell volume recovery, a process known as regulatory volume decrease (RVD). In many cell types, there is an evidence that the cytoskeleton may play a role in the initial sensing and transduction of the signal of volume change. In this study, we tested the hypothesis that an intact microfilament and microtubule network is required for volume response and RVD in boar sperm before and after capacitation treatment and whether addition of cytochalasin D and colchicine to the capacitation medium would affect volumetric behaviour. Capacitation is a series of cellular and molecular alterations that enable the spermatozoon to fertilize an oocyte. Cell volume measurements of washed sperm suspensions were performed electronically in Hepes-buffered saline solutions of 300 and 180 mosmol/kg. After exposure to hypoosmotic conditions, boar sperm showed initial swelling (up to 150% of initial volume within 5 min), which was subsequently partially reversed (to about 120–130% after 20 min). Treatment with cytochalasin D led to reduced initial swelling (1 μmol/l) and loss of RVD in washed sperm (1–10 μmol/l) and at the beginning of incubation under capacitating conditions (5 μmol/l). Short treatment with 500 μmol/l colchicine affected the volume regulatory ability in sperm under capacitating conditions but not in washed sperm. No significant differences in cell volume response were observed after subsequent addition of cytochalasin D and colchicine to the suspensions of sperm incubated for 3 h under capacitating conditions. However, the incubation under capacitating conditions in the presence of cytochalasin D led to improved volume regulation at the end of the incubation period (23%). The microfilament network appears to be important for volume regulation in washed boar spermatozoa while intact microtubules do not seem to be necessary for osmotically induced RVD. The changes in cytoskeleton microfilament organization during capacitation, possibly affecting the osmotically induced volume response, appear to occur at the later stages of capacitation, whereas changes in microtubules, related to volume regulatory ability, may be programmed within the first stages of capacitation.


Reproduction ◽  
2001 ◽  
pp. 327-336 ◽  
Author(s):  
AM Petrunkina ◽  
RA Harrison ◽  
M Hebel ◽  
KF Weitze ◽  
E Topfer-Petersen

The ability to reverse swelling caused by hypo-osmotic stress is an important cell function; in spermatozoa, it is likely to be of consequence during ejaculation and also during the thawing process that terminates cryopreservation. In this study, the time course of boar and bull sperm volume changes after exposure to hypo-osmotic conditions at 39 degrees C was recorded. Cell volume measurements of washed sperm suspensions were performed electronically in Hepes-buffered saline solutions of 300 and 180 mosmol kg(-1) containing 2.5 mmol K(+) l(-1). Treatment with quinine in the presence or absence of the potassium ionophore valinomycin was used to determine whether potassium channels were involved in the reversal of swelling. After exposure to hypo-osmotic conditions, both bull and boar spermatozoa showed initial swelling (up to 200% and 140% of initial volume, respectively, within 5 min), which was subsequently partially reversed (to about 150% and 120%, respectively, after 20 min). Incubation with quinine led to an increase in swelling in both species. However, bull sperm volume was already maximal (up to 294%) after 30 s and declined thereafter, whereas boar sperm volume increased slowly to a maximum of about 220% after 20 min. Valinomycin treatment caused quinine-induced swelling in bull spermatozoa to decrease rapidly to control (no quinine, no valinomycin) values, whereas in quinine-treated boar spermatozoa it had an opposite, enhancing effect. Interpreting these results in the light of data from studies by others on a variety of cell types, it is proposed that swelling-activated potassium channels are involved in regulatory volume decrease in both species of spermatozoa, but that boar spermatozoa may contain fewer swelling-activated chloride channels than do bull spermatozoa.


1987 ◽  
Vol 252 (5) ◽  
pp. F922-F932 ◽  
Author(s):  
K. L. Kirk ◽  
J. A. Schafer ◽  
D. R. DiBona

Volume regulation in the perfused proximal nephron of the rabbit was examined quantitatively with a computer-based method for estimating cell volume from differential interference-contrast microscopic images of isolated nephron segments. Following a hyperosmotic challenge (290-390 mosmol), the cells shrank as simple osmometers without a subsequent regulatory volume increase. Conversely, cell swelling induced by a hyposmotic challenge (290-190 mosmol) was completely reversed with a triphasic time course in which a rapid (less than 2 min) initial volume decline was followed by secondary swelling and shrinking phases. A similar regulatory volume decrease was observed following isosmotic cell swelling that was induced by exposure to 290 mosmol, urea-containing solutions. In addition, the cells partially reversed isosmotic swelling that was induced by the luminal replacement of a relatively impermeant cation (i.e., choline) with Na+ and a concomitant increase in luminal solute entry. Our results support two conclusions. First, there exist quantitative differences between the volume regulatory behaviors of perfused and nonperfused proximal tubules, the latter of which exhibit an incomplete and monotonic reversal of hyposmotic cell swelling (M. Dellasega and J. Grantham, Am. J. Physiol. 224: 1288-1294, 1973). Second, the primary physiological role of cell volume regulation in the proximal nephron may be to minimize isosmotic cell swelling associated with acute imbalances in the rates of cell solute entry and exit.


Reproduction ◽  
2000 ◽  
Vol 118 (2) ◽  
pp. 283-293 ◽  
Author(s):  
A. Petrounkina ◽  
R. Harrison ◽  
R Petzoldt ◽  
K. Weitze ◽  
E Topfer-Petersen

1999 ◽  
Vol 82 (1) ◽  
pp. 320-329 ◽  
Author(s):  
Norman R. Kreisman ◽  
Joseph C. LaManna

The role of swelling in hypoxic/ischemic neuronal injury is incompletely understood. We investigated the extent and time course of cell swelling during hypoxia, and recovery of cell volume during reoxygenation, in the CA1 region of rat hippocampal slices in vitro. Cell swelling was measured optically and compared with simultaneous measurements of the extracellular DC potential, extracellular [K+], and synaptic transmission in the presence and absence of hypoxic depolarization. Hypoxia-induced swelling consisted of rapid and/or slow components. Rapid swelling was observed frequently and always occurred simultaneously with hypoxic depolarization. Additionally, rapid swelling was followed by a prolonged phase of swelling that was ∼15 times slower. Less frequently, slow swelling occurred independently, without either hypoxic depolarization or a preceding rapid swelling. For slices initially swelling rapidly, recovery of both cell volume and the slope of field excitatory postsynaptic potentials were best correlated with the duration of hypoxia ( r = 0.77 and 0.87, respectively). This was also the case for slices initially swelling slowly ( r = 0.70 and 0.58, respectively). In contrast, the degree of recovery of cell volume was the same at 30 or 60 min of reoxygenation, indicating that prolonging the duration of reoxygenation within these limits was ineffective in improving recovery. Spectral measurements indicated that the hypoxia-induced changes in light transmittance were related to changes in cell volume and not changes in the oxidation state of mitochondrial cytochromes. The persistent impairment of synaptic transmission in slices swelling slowly (i.e., without hypoxic depolarization) indicates that swelling may play a role in this injury and that hypoxic depolarization is not required. Additionally, the correlation between the degree of recovery of cell volume and the degree of recovery of synaptic transmission during reoxygenation supports a role for swelling in hypoxic neuronal injury.


Reproduction ◽  
2003 ◽  
pp. 377-387 ◽  
Author(s):  
AM Petrunkina ◽  
A Lakamp ◽  
M Gentzel ◽  
M Ekhlasi-Hundrieser ◽  
E Topfer-Petersen

Polyclonal avian antibody was used partially to characterize the pig sperm lactadherin P47. P47 is a mosaic protein, composed of two epidermal growth factor (EGF)-like domains and two C1/C2 domains. P47 is homologous to the bovine mammary gland protein MGP 53/57 and mouse milk fat globule protein. Expression of P47 along the male genital tract and its localization on spermatozoa during post-testicular maturation and capacitation were studied. P47 was detected in the testis and in all parts of the epididymis by immunohistochemistry and by western blots of tissue extracts. By indirect immunocytochemistry, P47 was localized at the apical ridge of the sperm head in testicular, epididymal and ejaculated spermatozoa. The fluorescence intensity progressed during sperm transit from caput to cauda epididymis, probably caused by the ongoing expression and subsequent accumulation of P47 on the sperm surface. During the time course of capacitation, P47 appears to be unmasked by the release of coating proteins and appears to migrate from the apical ridge onto the entire acrosomal region, showing an intensive fluorescence pattern after 3 h capacitation in vitro. The kinetics of signal changes during in vitro capacitation were different in epididymal and ejaculated spermatozoa, indicating accelerated capacitational plasma membrane destabilization in epididymal spermatozoa.


1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.


1985 ◽  
Vol 54 (04) ◽  
pp. 842-848 ◽  
Author(s):  
Kandice Kottke-Marchant ◽  
James M Anderson ◽  
Albert Rabinovitch ◽  
Richard A Huskey ◽  
Roger Herzig

SummaryHeparin is known to affect platelet function in vitro, but little is known about the effect of heparin on the interaction of platelets with polymer surfaces in general, and vascular graft materials in particular. For this reason, the effect of heparin vs. citrate anticoagulation on the interaction of platelets with the vascular graft materials expanded polytetrafluoroethylene (ePTFE), Dacron Bionit (DB) and preclotted Dacron Bionit (DB/PC) was studied in a recirculating, in vitro perfusion system. Platelet activation, as shown by a decrease in platelet count, an increase in platelet release and a decrease in platelet aggregation, was observed for all vascular graft materials tested using heparin and was greater for Dacron and preclotted Dacron than for ePTFE. Significant differences between heparin and citrate anticoagulation were seen for platelet release, platelet aggregation and the relative ranking of material platelet-reactivity. However, the trends and time course of platelet activation were similar with both heparin and citrate for the materials tested.


Sign in / Sign up

Export Citation Format

Share Document